Air pump



Jan. 27, 1925. 1,524,052

w. F. PAGEL AIR PUMP Filed Nov.' 25, 1921 Patented Jan.. 27, 192i.

WILLIAM F. PAGEL, OF SYCAMORE, ILLINOIS.

Application le'd November 25, 1921. Serial No. 517,430.

To all whom it may concern' Be it known that I, IVILLIAM F. PAGEL, a citizen of the United States, and resident of Sycamore, in the county of De Kalb and State of Illinois, have invented certain new and useful Improvements in an Air Pump, of which the following is a specification.

My invention relates to improvements in air pumps and has special reference to pumps for applying air pressure to plumbers torches.

rThe object of my invention is to provide a pump piston of the leather cup kind in which the leather cup is constantly lubricated; in which the leather cup shall be eX- panded on the pressure stroke andshall be readily contractable on the suction stroke to the end of greatly increasing the efficiency, and 'facilitate the yoperation of such pumps.

A further feature of importance relates to the provision of an open chamber in the piston head for lubricant, which chamber is sealed or closed by the leather cup itself.

Further advantageous features of construction and operation will appear hereinafter.

My invention will be more readily understood by reference to the accompanying drawings forming part of this specification, and in which Figure 1 is a 'fragmentary side elevation of a plumbers torch provided with an air pump made in accordance with my invention and shown in vertical section;

Figure 2 is an enlarged fragmentary central section of the lower end of the pump;

Figure 3 is a horizontal sectional view on the line 3 3 Iof Figure 2;

Figure 4 is a vertical sectional view similar to Figure 2 showing a slightly modified form of piston head;

Figure 5 is a horizontal sectional view on the line 5-5 of Figure 4; and

Figure 6 is a top plan view of another form of piston head.

In said drawings, 1 represents a plumber`s torch yof the usual 'form adapted to supply fuel oil to the burner of the torch by air pressure. The torch is usually provided with an air pump mounted upon or attached to the reservoir of the torch for supplying the air pressure. I provide a pump 2 comprising a thin wall pump cylinder 3 mounted at its lower end in the 'outer end 4 of a bracket 5 which is attached rigidly to the torch reservoir and adjacent to the upper vtween the piston and the cylinder.

end of the cylinder it is received and held in the outer end 6 of a rigid bracket 7. Within the cylinder 3 I provide a reciprocable piston 8 rigidly mounted on the lower end of a piston rod 9 which projects through the upper end 'of the pump cylinder 3 and is provided on its upper end with a knob 10 for hand operation of the piston. The piston is of the leather cup kind and is provided with a leather cup 11 adapted to be secured in position on the piston rodbetween a metal washer 12 and a metallic piston head 13 in the usual manner. The piston head is threaded upon the lower end of the piston rod and is adapted to clamp the washer 12 and the base of the leather cup 11 against the shouldered lower end of the piston rod. Instead of making the head 13 substantially completely filling the leather cup according to the usual practice I provide a space between the upper part of the piston head within the cup as shown at 147 Figures l and 2, to permit the side wall 15 of the leather cup to readily contract on the suction stroke and thus reduce friction be- I also provide means such as vertical grooves or notches 16 to permit the air to readily enter into this space on the pressure stroke Iof the piston and expand the cup against the cylinder wall thus preventing any escape of air past the piston on the pressure stroke. The air readily enters through the y upper end of the cylinder around the piston rod on the pressure stroke to follow the piston and as the cup readily contracts on the suction stroke the air easily passes the piston on this stroke.

I have found tha-t in such air pumps, especially when used in connection with devices which make use of gasolene or similar fuels, that the leather cup soon dries up and becomes hard and usually must then be removed and replaced by a new cup. To avoid this difficulty I provide the metallic piston head 13 with'a chamber 16 preferably in the form of a circumferential groove between a central hub 17 and the open space 14 and when assembling the piston head, I pack this groove 16 full of vaseline or some similar lubricant. It will be seen that this chamber which is adapted to be filled with lubricant is sealed or closed by the base 18 of the leather cup and that consequently the cup is in constant contact with the lubricant and is adapted to be conlIO ' info-a valve chamber 253in-said'bracket and theinterior ofl the torch reservoir.

Vbeneath the piston to the seat;

vstroke into the*circumferential space 14.

Instead of tapering the piston head as described I may make it With straight sides as shownl in,Figures 4 and 5 providing a circumferential groove 2O at 'the outer corner of its upper surfacev andv provide a plurality of longitudinal vertical grooves or notches 2'1 in its periphery tol permit the air to enter into the circumferential groove 20Land1 expand? the leather cup 1 on the pressurestroke.-

Instead of lprovidingl a circumferential groove'in the'upper endy of the piston head, If may simply providethe'periphery ofthe piston head with a plurality of vertically extending grooves or notches 22 as shown in Figure 6 providing suflicient ofk these grooves-f topermit the air to enter in betweenthe upperend" ofthe piston head andi the Vbottom of the cup and effect the expansion-ofl the cup'iny an obvious manner.

I preferably provide a compression spring 23 mounted loosely' on the piston rod above the piston head and adapted to cushion` Yt-her piston at the upper limit of the suction stroke.

For delivering the compressed air from torch I provide a central port 24;l inl the bracket 41 which leads I provide a horizontal passage 26y inv the bracket connecting the valve chamber with.

valve chamber 25 is closed at-itslower end by a'screW plug 26 and Within the chamber I provide a check valve 27 comprisingy a cork -orf'similar yielding disk 28 mountedA within a metallic head 29'Which is carried on avertical stem 30.Y The outer Wall 31 ofthe head 29 is formed over the outer edge ofthe cork disk! to retain the disk in the head and Ij preferably provideV a y narrow valveseat 32 around t 'repassage-24 against Which the cork disk'is-adapted tol bef yieldingly heldV by the pressurewithinthe reservoir and by a. compression spring 23 mounted on thestem 30 yand adapted' to push' the valve 27 upwardly against the The lower end of The the `stem 27 is guided in a. central guide opening 3l in the screw plug 26.

As the lower end of the metallic piston head is substantially flush with the lower edge ofthe Wall of the leather cup, substantially all of the air is expelled from the Vcylinder on each pressure stroke. The only air remainingr iuicxpelled being that in the short small passage 24: and consequently there is substantially noreaction from the many operatl a As many modifications of' my inventionwill readily suggest themselves to one skilled in the art I do' not limit or confine my invention to the specific. details of construction herein shown and described.

I- claim:

1. In an air pump, a cylinder, apiston in the cylinder, means for reciprocating the piston, the piston comprising a cup of leather or the like and a metallic head within the cup, the head provided in its inner end withan openchamber for lubricant, said chamber being sealed by the leather cup.

2. 1n an air pump, a cylinder, aA piston reciprocable in the cylinder, the piston comprising. a cup of leather'or tliclike and a metallic piston head Within they cup, the head tapered longitudinally bein smaller at its inner end and substantial y fitting Within the cup at itsA outer end and provided W'itl'i passages for permitting the air to enterbetween the piston and the cup on the pressuie stroke, the Small inner end of the piston provided with a circumferential groove adapted to befilled with lubricant such as vaseline,- the groove being scaled bythe base of ther-cup, as and for the purpose specified.

3. In a piston for an air pressure cylinder the piston con'iprising a leather cup and a Vmetallic head within and substantially fillingr the cup, -the head provided with an opening for receiving a material such as vaseline for keeping the leather soft, and thebase of the leather cup sealin said opening asandV for the purpose specified Signed at Sycamore, Illinois, this 10th day of November, 1921.

VILLIAM F. PAGEL.

in substantially bil 

